New ASCO guidance narrows when PARP inhibitors should be used in ovarian cancer
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Everyone newly diagnosed with advanced ovarian cancer should get genetic testing, and PARP inhibitor maintenance should be prioritized after the first remission, says an American Society of Clinical Oncology living guideline published Oct. 27, 2026, in Journal of Clinical Oncology. The update affects one of the deadliest women’s cancers.
PARP inhibitors, such as olaparib, are pills that exploit a weakness in tumors that can’t repair DNA properly, often because of BRCA1/2 mutations. They changed ovarian cancer care. But newer data showed that, in some settings, they may not help people live longer.
What is a living guideline?
It’s a set of recommendations from an expert panel that is updated regularly as new evidence appears. This version is based on 79 publications, including 18 studies of 13 tests for homologous recombination deficiency (HRD), a DNA repair defect, and 31 major trials of PARP inhibitors.
What does it recommend?
- Testing for all: everyone with newly diagnosed advanced epithelial ovarian cancer should get genetic testing, and HRD testing of the tumor if BRCA-negative, with approved or validated tests.
- First remission is key: maintenance with a PARP inhibitor should be prioritized after the first response to platinum chemotherapy, for people with BRCA1/2 mutations or HRD-positive tumors.
- Not for everyone: PARP inhibitors are not recommended for tumors without BRCA mutations that are HRD-negative, or for early-stage disease.
- Later use, restricted: in recurrent disease, maintenance should mainly be for people with BRCA1/2 mutations who haven’t had a PARP inhibitor before; PARP inhibitors alone shouldn’t be used as treatment for recurrence outside trials, nor combined with other drugs outside trials.
- Safety: doctors should watch for rare but serious problems, including myelodysplastic syndrome, acute myeloid leukemia and lung complications.
Why does this matter for women’s cancers?
Trials using PARP inhibitors early showed clear gains in time without progression, while later-line and recurrent maintenance trials hinted at possible survival disadvantages. The guideline focuses the drugs where the benefit is clearest.
How solid is this evidence?
It’s strong as guidance. Mongevity rates it A on our A-to-E scale: a systematic review of randomized trials by an expert panel. Recommendations still require judgment for each patient.
What does this mean for you?
If you or someone close to you has newly diagnosed advanced ovarian cancer, ask whether genetic and HRD testing have been done. The results guide whether a PARP inhibitor makes sense and when. Family members may also benefit from genetic counseling.
How do I explain this at dinner?
Some ovarian cancers have a broken repair kit for their DNA. Special pills attack that weakness, and experts now say they work best right after the first treatment, in the right patients. A good question for the table: why does timing matter for medicine?
In one sentence: ASCO’s updated guideline calls for genetic testing in all advanced ovarian cancer and focuses PARP inhibitors on the first remission in the right patients.
Questions and answers
- What are PARP inhibitors?
- Pills, such as olaparib, that target tumors unable to repair DNA properly, often due to BRCA1/2 mutations or HRD.
- Who should get genetic testing?
- Everyone with newly diagnosed advanced epithelial ovarian cancer, plus HRD testing of the tumor if BRCA-negative.
- When should PARP inhibitors be used?
- Mainly as maintenance after the first response to platinum chemotherapy in BRCA-mutated or HRD-positive disease; use later on is restricted.
